The goal of this proposal is to determine the ways in which an unstudied risk/protective factor - Morningness/Eveningness- contributes to alcohol abuse etiologies and prevention. The thrust of our efforts is a theoretically derived examination of a wide array of assessments of social functioning and alcohol abuse. The proposed project consists of further preparation and secondary analysis of data from four Swedish longitudinal and cross-sectional studies. In the developmental framework that guides the research, alcohol problems develop or diminish in configurations with other individual attributes and are embedded within social circumstances across the life cycle. We are concerned with processes that underlie behavioral continuities and changes. Theoretical support is provided by finding that stable individual differences in light/dark entrainment and associated physiological states of arousal and fatigue -- Morning- and Evening-types -- first emerge at 6 months. For M-types, morning arousal is consistent with cultural expectations and related to adaptive functioning at home and in school. For E-types, morning fatigue and evening arousal are linked to risk factors, including alcohol abuse, school disaffection, conflicts with parents, and antisocial behavior. Exceptions to findings, i.e., resilient E-types and vulnerable M-types are of importance. Traditional univariate and multivariate statistical procedures will be used when appropriate to the data. For other purposes, a person-oriented approach will be used to identify homogenous configurations through cluster analyses; developmental trajectories of resultant configurations will be tested in conjunction with hierarchical linear modeling (HLM). Specific aims include: (1) test predictions that psychological functioning and interactions with parents will not differ for E- and M-types in infancy and early preschool years, but appear with increased demands for morning performance by age 5; (2) test predictions that low morning arousal indicators, including fatigue, dark moods, and depression will be related to Eveningness, but unrelated to alcohol abuse; depression in M-types, particularly females, may be associated with alcohol abuse; and (3) map configurations of risk and resilience at different points in development to clarify multiple etiologic processes and demonstrate that developmental systems theory links disparate outcomes.